An interventional study of PKU sphere in Phenylketonurias and PKU, sponsored by Vitaflo International, Ltd. Completed at 4 sites in Italy. Open to participants aged 3 Years and older. Per ClinicalTrials.gov, last updated 2026-05-14.
Sponsored by Vitaflo International, Ltd (part of Nestlé S.A.) · Not applicable, Interventional, and Supportive care
20 participants with PKU will build-up their dietary intake of PKU sphere over 2-16 weeks, depending on their level of metabolic control whilst doing so. Participants will complete a gastrointestinal specific and PKU specific questionnaire at the Baseline clinic visit and record the amount of PKU sphere taken each day. Dried blood spots are taken twice per week.
Once built up to a clinically appropriate intake of PKU sphere, or after 16 weeks, participants enter a 4-week Evaluation Period. The amount of PKU sphere taken per day continues to be recorded by participants. Gastrointestinal tolerance over the preceding seven days is recorded at the end of each week. Evaluations of PKU sphere's palatability are made at the end of weeks two and four of the Evaluation Period. Dried blood spots are taken once per week.
The participant attends an End of Study Visit at the clinic and the investigator decides whether they should continue taking PKU sphere.
20 participants with phenylketonuria (PKU) will introduce PKU sphere into their diet. PKU sphere is a food for special medical purposes (as defined by Regulation (EU) No 609/2013 on food for specific groups), used for the dietary management of phenylketonuria from 3 years of age.
The study begins with a Baseline clinic visit. Informed consent is taken by the investigator before the participant completes a PKU specific quality of life questionnaire, and a GI specific questionnaire. The participant takes a dried blood spot in order for the investigator to check their technique is correct.
Build-up and Stabilisation Period. This will last between 2 and 16 weeks, depending on how long the participant takes to reach their maximum recommended intake of PKU sphere. Participants will take a dried blood spot twice per week in order for their health care professional to monitor their phenylalanine and tyrosine levels. After three consecutive dried blood spot results within the target range, the participant's HCP can advise to swap one portion of amino acid-based protein substitute for PKU sphere. This method of building up the amount of PKU sphere to be taken is informed directly by Vitaflo's 'Practical Guide to PKU sphere'. The amount of PKU sphere taken each day is recorded by the participant in their study diary.
Once the maximum recommended amount of PKU sphere is being taken by the participant, or after 16 weeks, the participant moves into the four-week Evaluation Period. Participants then take a dried blood spot once per week, but continue to record their intake of PKU sphere each day. At the end of each Evaluation Period week, participants record any gastrointestinal symptoms experienced over the preceding seven days. At the end of Evaluation Period weeks two and four, participants will also record their thoughts on PKU sphere's palatability. This includes a Likert scale rating of the product's appearance, taste, aftertaste, smell, texture, packaging and ease of use.
At the end of the Evaluation Period, participants return to the clinic for the End of Study visit. The PKU and GI specific questionnaires completed at Baseline are repeated and the Investigator discusses the suitability of the participant to continue to take PKU sphere as part of their regular therapeutic diet. Following the visit, the Investigator rates the utility of the Practical Guide to PKU sphere. A Follow-up Phone Call will relay the results of any outstanding dried blood spot results to participants following their End of Study Visit.
191 studies on the registry are indexed under Phenylketonurias; 40 are open to participants now.
This study's enrollment of 13 is below the median of 27 across 122 interventional studies indexed under Phenylketonurias.
Browse Phenylketonurias studies →Vitaflo International, Ltd is the lead sponsor of 23 studies on the registry; none are open to participants now.
First submitted after Vitaflo International, Ltd became part of Nestlé S.A..
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All patients to recieve PKU sphere as part of their dietary management for phenylketonuria (PKU)
Dietary Supplement: PKU sphere
TYR sphere is a powdered, low phenylalanine and tyrosine protein substitute, containing a balanced mix of casein glycomacropeptide (cGMP) isolate, essential and non-essential amino acids, carbohydrate, fat, vitamins, minerals and the long chain polyunsaturated fatty acid (LCP); Docosahexaenoic acid (DHA). It contains sugars and sweetener. The product is designed to be prescribed based on its protein content, not its energy content.
Change in adherence to recomended amounts of PKU sphere
Patient reported data on actual compared to prescribed intakes of PKU sphere
Time frame: Recorded daily from start of 2-16 week Build-up and Stabilisation Period to end of 4 week Evaluation Period, assessed by HCPs periodically as per routine practice.
Change in gastrointestinal tolerance
Patient reported data on any gastrointestinal symptoms experienced
Time frame: Data on previous 7 days collected by patients at the end of each Evaluation Period week. This data will be assessed by HCPs periodically as per routine practice.
Patient evaluation of PKU sphere's palatability, Evaluation Period week 2
Patient reported Likert-scale evaluation of PKU sphere's appearance, smell, taste, aftertaste, texture, packaging/presentation and ease of use. A higher score denotes a more positive response.
Time frame: End of Evaluation Period week 2.
Patient evaluation of PKU sphere's palatability, Evaluation Period week 4
Patient reported Likert-scale evaluation of PKU sphere's appearance, smell, taste, aftertaste, texture, packaging/presentation and ease of use. A higher score denotes a more positive response.
Time frame: End of Evaluation Period week 4.
Change in metabolic control (phenylalanine) over Build-up and Stabilisation Period.
Phenylalanine levels obtained from dried blood spots
Time frame: Dried blood spots taken twice weekly during 2-16 week Build-up and Stabilisation Period.
Change in metabolic control (phenylalanine) over Evaluation Period.
Phenylalanine levels obtained from dried blood spots
Time frame: Dried blood spots taken once weekly during 4-week Evaluation Period.
Change in metabolic control (tyrosine) over Build-up and Stabilisation Period.
Tyrosine levels obtained from dried blood spots
Time frame: Dried blood spots taken twice weekly during 2-16 week Build-up and Stabilisation Period.
Change in metabolic control (tyrosine) over Evalaution Period.
Tyrosine levels obtained from dried blood spots
Time frame: Dried blood spots taken once weekly during 4-week Evalaution Period.
Change in gatrointestinal quality of life
Age-specific, GI related quality of life questionnaire completed by participants. The specific version of the questionnaire to be used by each age group is listed below: Age 2-4 years (Parental completion) = MAPI PedsQL Gastrointestinal Symptoms Scales, Toddlers (2-4) Age 5-7 years (Parental completion) = MAPI PedsQL Gastrointestinal Symptoms Scales, Young Children (5-7) Age 8-12 years (Parental completion) = MAPI PedsQL Gastrointestinal Symptoms Scales, Children (8-12) Age 13-18 years = MAPI PedsQL Gastrointestinal Symptoms Scales, Teens (13-18) Age 18 years and upwards = Birmingham IBS Symptom Questionnaire The MAPI PedsQL Gastrointestinal Symptoms Scale questionnaires and the Birmingham IBS symptom Questionnaire indicate fewer problems with higher calculated scores.
Time frame: Baseline visit (day one) and End of Study visit (post day-28 of Evaluation Period)
Change in PKU specific quality of life
Age-specific, PKU related quality of life questionnaire completed by participants. The specific version of the questionnaire to be used by each age group is listed below: Age \>9 years = MAPI phenylketonuria impact and treatment Quality Of Life Questionnaire (PKU-QOL), Parents Age 9-11 years = MAPI phenylketonuria impact and treatment Quality Of Life Questionnaire (PKU-QOL), Children Age 12-17 years = MAPI phenylketonuria impact and treatment Quality Of Life Questionnaire (PKU-QOL), Adolescent Age 18+ years = MAPI phenylketonuria impact and treatment Quality Of Life Questionnaire (PKU-QOL), Adult With all versions of the PKU-QOL, a higher calculated score denotes higher quality of life.
Time frame: Baseline visit (day one) and End of Study visit (post day-28 of Evaluation Period)
Plan to share: No
No publications or documents are linked to this record.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.